Data storage systems have tended to be made ever smaller, yet with ever greater storage capacity, as technology has advanced. Such data storage systems are usefully applied in a wide variety of settings including computers, networks, digital music players, PDAs, digital still cameras and video cameras, and external computer memory, among a wide variety of other possible examples. One limit on the performance of a data storage system is the accuracy with which the system can evaluate and control the position of a read/write head or other form of read head relative to the positions of data within the system. Providing data storage technology with optimum performance in current applications poses considerable technical challenges. However, there remains a persistent need for providing data storage systems that are ever smaller, yet with ever greater storage capacity and superior performance characteristics.